Electrochemical Regioselective C(sp2)-H Selenylation of Pyrazolo[1,5-a]pyrimidines with Diorganyldiselenides at Room Temperature

In this report, we disclose an electrochemical approach for the C(sp2)-H selenylation of pyrazolo[1,5-a]pyrimidines at room temperature. The reaction takes place within an undivided cell employing graphite electrodes, with TBABF4 acting as the supporting electrolyte. This technique offers a rapid, oxidant as well as halogen free, and environmentally conscious protocol for achieving regioselective selenylation specifically at the C3 position of pyrazolo[1,5-a]pyrimidines. Key attributes of this methodology include its atom economy, mild reaction conditions, short reaction time, utilization of cost-effective electrode materials, reliable achievement of yields ranging from good to excellent, and an environmentally friendly reaction condition.